If you want to jump right into messaging people from the personals, there's certainly nothing wrong with that.

But the idea of participating on the discussion board too is that you'd also . . . discuss.
Some topics.
On here, on the board.

There are many of them that invite your commentary or opinion.

Discussion here would mean other members can see what you're like via more than just your personals profile. (But for that, you probably want to give them a little more to go on than, "Anyone out there?")